Fractionation of tall oil



Nov. 21, 1950 R. M. CHRISTENSON ET AL 2,530,809

FRACTIONATION 0F TALL OIL Filed Aug. 23, 1949 5 Sheets-Sheet 1 NAPHTHA8c TALL OIL F G 1 UNSAPTNIFIABLES T SOLIDS FR M 1 WATER NAPHTHA 8c TALLOIL SAPONIFICATION unsAPoHIFIABLm OF TALL OIL & LOWER ALCOHOL & WATER III COMM-CURB]!!! BM'RAOTION ZONE.

COUNTER- CURRENT EXTRACTION ZONE WASH WATER s: mum OF I4r- 'TALL OILsons SOAPS-- 6 ACID IFIER 4, INVENTORS ROGER m. CHRSTENSO 4W0 srewmr w.GLOYER Gas/5 ATTORNEY 1950 R. M. CHRISTENSON ET AL 2,530,809

FRACTIONATION 0F TALL OIL Filed Aug. 25, 1949 5 Sheefs-Sheet 2 FIG?SAPONIFIED TALL OIL SEPARATION IN THE. SYSTEM SAPONIFIED TALL OILISOPROPANOL-WATER- NAPHTHA AT 80F.

AREA OF POOR SEPARATION AREA OF POOR SEPARATION ISOPROPANOL AREA OFFAIR/ AREA OF GOOD NATE v SEPARATION SEPARATIOI INVENTORS 1y ROGER M.CHRISTENSON o STEWART W. GLOYEP.

AZTORAJ'Y Nov. 21, 1950 R. M. CHRISTENSON ET AL 2,530,809

FRACTIONATION 0F TALL on.

Filed Aug. 23, 1949 S-Sheets-Sheet 3 FIG.3

SAPONIFIED TALL OIL C SEPARATION OF THE SYSTEM SAPONIFIED TALL OILISOPROPANOL- WATER-NAPHTHA AT 120 F.

AREA OF POOR I AREA OF POOR SEPARATION SEPARATION Q WWW WA A n I y n BISOPROPAROL AREA OF GOOD SEPARATION WATER AREA OF FA IR SEPARAT ION kafiATTORNEY Nov. 21, 1950 R. M. CHRISTENSON ET AL 2,530,809

FRACTIONATION 0F TALL OIL Filed Aug. 23, 1949 5 Sheets-Sheet 4SAPONIFIED TALL OIL SEPARATION IN THE SYSTEM SAPONIFIED TALL OIL UNDERMETHANOL-NAPHTHA AT 80F.

AREA OF POOR AREA OF POOR SEPARATION SEPARATION METHANOL AREA OF GOODSEPARATION WATER INVENTORS ROGER m. CHRISTENSON BPTEWART w. GLO! ER Nov.21, 1950 R. M. CHRISTENSON ET AL 2,530,809

' FRACTIONATION 0F TALL OIL Filed Aug. 23, 1949 5 Sheets-Sheet 5 FIGSSEPARATION OF THE SYSTEM SAPONIFIED TALL SAPONIFIED TALL OILMEI'HANOL-WATER-NAPHTHA WWWWW METHANOL AREA OF PbOR SEPARATION AREA OFGOOD SEPARATION WATER INVENTORS 4 ROGER M CHRISTENSON STEWART W. GLOYERwas/5 Patented Nov. 21, 1950 FRACTIONATION OF TALL OIL Roger M.Christenson and Stewart W. Gloyer, Milwaukee, Wis., assignors toPittsburgh Plate Glass Company Application August 23, 1949, Serial No.111,804

6 Claims.

The present invention relates to the treatment of the residues orby-products from the manufacture of paper pulp and it has particularrelation to the treatment of the residues or byproducts known as talloil soaps obtained in the waste liquors from the digestion of pine woodin order chemically to convert it into paper pulp.

One object of the invention is to recover sterols from the by-productsabove indicated in a form suitable for use in the preparation of sexhormones, wetting agents and other valuable products. r

A second object is to increase the yield of valuable distilled fattyacids and rosin acids recoverable from tall oil or tall oil soaps.

A third object is to provide rosin acids and and fatty acids havingimproved drying characteristics when incorporated into paintcompositions.

A fourth object is to provide a process of obtaining the sterols andother useful components of tall oil in which the unsaponfiable mattercontaining the sterols is extracted directly by counter-current methodsfrom the crude paste of soaps of tall oil acids and unsaponiflablematter as obtained in the paper industry.

These and other objects of the invention will be apparent fromconsideration of the following specification and the appended drawings.

In the drawings, Figure, l diagrammatically illustrates an embodiment ofapparatus suitable for use in the-'practice of the invention.

Figure 2 is a graph showing by triangular coordinates the approximatelimits at a lower temperature of the operable systems of tall oilsolids, water and isopropyl alcohol.

. Figure 3 is a similar curve for a higher operating temperature.

Figures 4 and 5 are graphs corresponding respectively to Figures 2 and 3but applying to the use of methanol as the alcoholic medium.

In the practice of the invention the following steps are employed:

Firstly, the crude by-product or residue from the manufacture of paperpulp known as the soaps of tall oil are admixed with a lower alcoholpreferably of the monohydric alkanol type and water to obtain a solutionof the tall oil soaps and the unsaponifiable matter associatedtherewith.

Secondly, the soap solution is subjected to extraction with a solventwhich is immiscible in, or but partially miscible with the soapsolutions and which is a, solvent for the unsaponiflable constituents ofthe tall oil. Solvents for the unsaponifiable matter appropriate for thepurpose include naphthas and other material which will be referred to ingreater detail subsequently. The extraction of the soap solution withthe solvent for the unsaponifiable matter may be conducted batchwise,but preferably it is conducted countercurrently in a packed column,although an unpacked column of suitable design, or other contactingdevice could also be employed.

Thirdly, the solution of unsaponifiable material extracted from the soapsolutions is washed with water to free it of any traces of soaps of talloil carried over therein.

Fourthly, the washed solution of unsaponifiable material rich insterols, coloring matter and any other unsaponiflable constituents issubjected to evaporation and stripping in order to eliminate thesolvent.

Fifthly, the crude unsaponifiable material rich in sterols is dissolvedin an appropriate solvent such as one of the lower alcohols or acetoneand subjected to crystallization in order to obtain the sterols inrelatively pure form.

Sixthly, if desired, the soaps of fatty acids and rosin acids in thewater-alcohol solution may be recovered in any convenient manner. Onesuch method of recovery would involve precipitation or salting out.Another convenient method would involve evaporation of the alcohol.

The soaps may then be treated with acid such as hydrochloric acid,sulfuric acid or other strong soluble acid designed to liberate the freefatty acids and free rosin acids. The free acids subsequently are washedwith water to remove salts and any residual mineral acids containedtherein. The mixture of acids may then be distilled under vacuum andobtained in a state of exceptional value for industrial application.

In Figure 1 is diagrammatically shown an embodiment of apparatus adaptedfor the countercurrent fractionation of the tall oil soaps.

The apparatus comprises columns I and II, the first of which is employedfor extracting the unsaponiflable matter by means of a solventrelatively immiscible with the soap solutions and the second of which isemployed in the operation of washing the solution of unsaponifiablematter in order to remove traces of soaps. In the practice of theinvention a solution of the crude byproduct termed tall oil soaps, madeup prefer-' ably in water and a lower alcohol in a manner hereinafterdescribed, is fed in to the column I near the top, thereof as indicatedat 3 and a solvent of the unsaponiilable matter relatively immisciblewith the water and alcohol is fed in near the bottom as indicated at 4.

A naphtha such as a heptane fraction from an aliphatic petroleumhydrocarbon constitutes a good solvent for the unsaponiflable material.It will be appreciated that if the solvent for the unsaponifiablematerial is of greater density than the soap solutions, it may be fed inat the top of the column I while the soap solutions are fed in at thebottom.

The aqueous alcohol solution of soap'sflows as a liquid through thecolumn countercurrently with respect to the solvent for theunsaponiflable matter and is drawn off from clearing zone a at thebottom of the column (assuming the soap solution be of the greaterdensity) as indicated at 5. The feed rate is dependent upon the size ofthe column, the nature of packing and such like factors, but should notbe so great as to cause mechanically entrained solvent of unsaponifiablematter to pass out of the column along with the aqueous alcohol or viceversa. This condition is easily observed. Very slow feeds areobjectionable because of unnecessarily low output but otherwise arepermissible. The soap solution passes to a still 6 for the removal ofsolvents contained therein. The mixture of soaps from which the solventshave been evaporated pass through a line I to a container 8 where theyare acidified in order to regenerate the free acids such as rosin acidsand fatty acids. The free rosin and fatty acids pass out from theacidifier through a line 9 to a container In which may be employed forpurposes of storage pending use or shipment of the material, or furthertreatment thereof. Such further treatment may, for example, comprisewater washing in order to remove salts and other water solublesubstances admixed with the free fatty acids and free rosin acids.Subsequently, the acids are distilled preferably under vacuum, e; g.vacuum of the order of 0.5 to 50 millimeters pressure. In this manneracids of high merit in the manufacture of coating composition, paints,and soaps are recovered. Only a small still residue remains after thedistillation operation.

The solution of unsaponifiable matter in naphtha or other appropriatesolvent immiscible with aqueous alcohol soap solution is drawn offat'the top (ifl column I from clearing zone I) through line For purposesof washing the solution to free it of residual soaps, the solution ispassed to column II at a point slightly above the bottom.Simultaneously, wash water is fed into the colmnn as indicated at l2slightly below the top and flows countercurrently through the solutionof unsaponifiable matter. The latter solution is drawn off through linel3 at the top of column II. Simultaneously, water containing residualsoaps and other water soluble constituents is drawn off as indicated atM and may be subjected to further treatment, e. g. to acidification toprecipitate free rosin and fatty acids or it may be discharged as wasteor dissolved alcohol may be recovered by distillation. Clearing zonesand d are provided respectively at the top and bottom of column II.

The naphtha solution of unsaponiflable matter containing a highpercentage of sterols may also be subjected to further treatment. Forexample, the naphtha may be evaporated. The sterols may then becrystallized out of a. solvent such as methyl alcohol, ethyl alcohol,acetone, or other appropriate solvent or solvent mixture and areobtained in a state of exceptional purity in which they are excellentlyadapted for use in the synthesis of pharmaceuticals, emulsifiers,anti-oxidants, and other products.

It will be appreciated that in the preparation of water-alcoholsolutions of the crude soaps and unsaponifiable matter of tall oil,various alcohols may be employed. These include methyl alcohol, ethylalcohol, normal propyl alcohol, isopropyl alcohol, butyl alcohol,isobutyl alcohol, and other alcohols notably of the alkanol type whichare water soluble, at least to a reasonable degree. Methanol, ethanoland isopropyl alcohol are especially suitable. Solutions may be made upto approximately the following composition:

Crude soaps of tall oil, 5 to and preferably Water soluble alcohol, e.g. isopropyl alcohol,

15-50% (preferably 16-27%).

Water, therest of the composition.

Any solvents for the unsaponiflable matter in tall oil and which areimmiscible with or only partially miscible with the water-alcoholsolutions may be employed to extract the unsaponifiable matter. In thisgroup may be included the various alkanes such as the heptanes, or theother petroleum fractions which are not excessively volatile or whichare not of such high boiling point as to be difficult to remove from theunsaponifiable matter by evaporation. Ethers, such as diethyl ether,methyl ethyl ether, isopropyl ether, ethyl or methyl isopropyl mixedethers, aromatic hydrocarbons such as benzene, toluene or xylene, orchlorinated hydrocarbons such as ethylene dichloride, and others may beemployed in the separation of the unsaponiflable matter from the soapsolutions. It is usually preferred to employ the solvent forunsaponiflable matter in a ratio of about 1 to l with respect to thesoap solution. However, this ratio may be much higher, for example 15 or20 parts by volume per part of soap solution. Lower ratios are alsocontemplated. A good working range for naphtha as the solvent ofunsaponiflable matter would be .5 to 10 parts by volume of naphtha perpart of soap solution subjected to extraction. Excessive increase of theratio of solvent for the unsaponiflable material tends to becomeuneconomical because of the large volumes of solvent which must behandled and the cost of evaporation. The following examples illustratethe practice of the invention:

Example I -In this example, isopropyl alcohol was employed with water asthe solvent medium. A tall oil soap obtained by evaporating a part ofthe liquids from the crude product as obtained from the paper makingindustry and containing about 60 per cent of solids including about 55per cent of soaps of rosin and fatty acids, was employed. No additionalalkali was required. This material was of pasty consistency andcontained unsaponifiable matter within a range of 4.8 to 6 per cent ofthe paste composition.

In order to prepare an extractable solution, 40 parts by weight of thepaste containing 24 parts of solids and 16 parts of water were dissolvedin 56 parts of water and 64 parts of isopropyl alcohol. This solutionwas then subjected to countercurrent extraction with a heptane fractionof petroleum hydrocarbon in column I. The soap solution was fed into thecolumn through line 3 the same column or could be passed through a.

succession of columns operated in a series where it could be washedrepeatedly with naphtha or other solvent for unsaponiflable matter.

The naphtha extract containing the unsaponiflable material from thecrude tall 011 soaps was subsequently washed free or soaps and alcoholand other water soluble constitutents in column 11. The washingoperation was conducted as follows:

Feed of naphtha containing unsaponiflable material, 80 parts by volume;

Water feed 240 parts by volume;

Temperature of washing approximately 130 to 150 F.

Other temperatures of washing could be employed. if so desired. The rateof feed is regulated to obtain satisfactory phase separation which, ofcourse, is a function of the packing and of the size of the column at agiven rate of feed and is readily determined by observing the output ofthe column to ascertain that additional phase separation does not occurif the solutions are left standing.

The naphtha was subsequently evaporated from the unsaponiflable materialto obtain a yield of 2.2 parts by weight of unsaponifiable material per40 parts of original paste or a yield of 5.5 per cent based upon theoriginal paste of soap subjected to treatment.

The crude unsaponifiable matter rich in sterols was dissolved inmethanol in a ratio of about 1 part sterol to parts methanol andcrystallized to yield 2.1 per cent of crude sterols based upon the talloil soap concentrate. The sterols had a melting point of 118 to 120 C.Digitonin precipitation indicated a purity of 75.6 per .cent. Thesesterols were further purified by decoloriza- .tion with charcoal andcrystallization from isopropanol to yield a fraction with a meltingpoint of 119 to 122 C. Digitonin analysis indicated a sterol content of82.1 per cent.

The mixture of soaps of rosin and fatty acids remaining in the water andalcohol from column I was subjected to evaporation to recover alcoholand naphtha which was returned to the process. The soaps were thenacidified, washed and distilled at a pressure of about 1 mm. Alight-yellow distillate suitable for use in the manufacture of alkydresins, soaps and many other purposes was obtained. The pot residue inthe still constituted only 7.8 per cent of the original paste solids. Incontra-distinction in conventional procedure where tall oil is subjectedto distillation in order to recover the acids thereof, the residuecomprises or per cent of the tall oil.

The following additional examples illustrate the separation of theunsaponifiable matter from crude tall oil soaps of the type previouslydescribed employing varying ratios of tall oil in a water-isopropylalcohol solution as a solvent.

I Separations were conducted at temperatures of I such as that disclosedin the drawing herein. In each instance the ratio of the immiscible orpart- 1y miscible solvent for unsaponiflable matter, e. g. naphtha ofheptane grade was 1 to 1 with respect to the solution of crude tall oilsoaps and unsaponinable matter in water and alcohol.

Example II A crude mixture or tell oil soaps containing unsaponiflablematter was made up in water and isopropyl'alcohol in a concentration of17.6 per cent. The alcohol was varied over a range of 19 to 37 per centin the water-alcohol-soap mixture. Clean separations of the naphtha fromthe soap solution in water and isopropyl alcohol were obtained over theentire range. The naphtha solu-.

tion of unsaponiilable matter could be washed with water to free it ofsoaps and certain other constituents. The resultant mixture ofunsaponiflable matter could be crystallized to obtain the sterols inrelatively pure form. The alcohol may be recovered from the soaps bydistillation and the fatty acids and rosin acids regenerated byacidification of the mixture. The acids could readily be fractionated bydistillation methods.

Example III In this example the crude mixture of tall oil acid soaps andunsaponiflabie matter was made up in water and isopropyl alcohol in aconcentration of 24 per cent. The isopropyl alcohol content of thesolution to be extracted Was varied within a range of 19 to 28.4 percent. Extractions were conducted at F. and again at F. and satisfactoryseparation of the naphtha solution of unsaponiflable matter from thewater and isopropyl alcohol solutions of soaps of rosin acids and fattyacids were obtained. The desired components of the two phases could berecovered in the manner previously described.

Example IV In this instance the crude mixture of tall oil acid soaps andunsaponiflable matter'was made up to a concentration of 29.6 per cent inwater and isopropyl alcohol. The isopropyl alcohol content of the soapmixture was varied over a range of 18 to 26 per cent. The extractionswith naphtha were conducted at 80 F. and at 120 F. with good results.

Solutions of crude tall oil soaps when made up as herein described andextracted with a solvent for unsaponifiable matter countercurrently, arenot subject to emulsification. Thorough and intimate contact of thealcoholic solutions with the solvent of unsaponifiable matter can beattained and quick and effective phase separation are still attained.Insofar as is known, these results have not heretofore been attained.With very high concentrations of both soap and isopropyl alcohol, thenaphtha tends to become too miscible; therefore. with soap solutions ofhigh concentration the isopropyl alcohol content should be reduced belowthe maximum attainable with solutions of low soap concentration.

In Figures 2 and 3 of the drawing are curves plotted upon triangularcoordinates illustrating appropriate systems of water isopropyl alcoholand solids of saponifled tall oil for countercurrent extraction withnaphtha as illustrated in Figure 1 of the drawings. In the graphs, thesides A-C constitute the isopropyl-alcohol-tall oil solids axes. SidesA-B constitute the isopropyl-alcohol-water axes and sides B-C constitutethe water-tall oil solids axes.

The graph in Figure 2 is based upon extractions conducted at 80 F. Thepercent of tall oil solidscomprising alkali, e. g. sodium soaps of rosinacids and fatty acids and unsaponiflable matter as previously described,may be as low as 5 or but usually for economies sake it is maintained ata higher figure. The tall oil solids employed were a conventional tailon product irom southern pine produced by the West Virginia Pulp & PaperCompany and sold under the "trade name of Tallso.

The limbs L and M are the approximate limits oi operability of .thesystem. The area on the graph between limbs L and M include the systemsof saponifled tall oil solids, water and alco- V l'i'ol which aresusceptible of countercurrent extraction with naphtha. The portion ofthe area below the branch is embodies systems or the three componentswhich at the temperature given are regarded as being especially suitablefor solvent extraction with naphtha countercurrently to removeunsaponiiiable matter from the soaps. In

this area, the naphtha and the solution of soaps in water and isopropylalcohol separate very rapidly and completely into layers which can bedrawn oif from each other for recovery of the tall 011 solids.

Figure 3 is a'similar graph illustrating operable systems forcountercurrent extraction with naphtha of tall oil solids in solution ofwater and isopropyl alcohol at a temperature of 120 F. In this curve,the area embraced between the branches 0 and P approximately includesthe of tall oil solidsin water and isopropyl alcohol is extremely rapidand complete and the separation of the unsaponifiable matter from thesaponifiable matter is relatively sharp.

It will be understood that any system falling within the areasdesignated in Figures 2 and 3 is liquid at the temperature given, is butpartially miscible with naphtha and does not form emulsions with thelatter matter. The solutions can be introduced at the top of anextraction zone such as the zone or column I of Figure 1 and will flowcountercurrently downwardly with relatively complete co-mingling andcontact with upwardly flowing naphtha introduced at the bottom of thesame zone. The naphtha solution of unsaponiflable matter containingsmall amounts of soaps of tall 011 acids passes off from the clearingzone b at the top 01' the column and can be readily washed with water toremove the soaps in the column II. Soap solutions in water and isopropylalcohol are drawn off at the bottom from clearing Excniple v In thisexample, a northern tall oil was'em ployed. The composition included 60%solids or which 8.8% was unsaponiflable material. The rest was mainlysodium soaps of tall oil acids. The composition included 40.0% of water.The saponifled tall oil solids were made into a solution comprising 30%tall oil solids 20% methanol 50% water The percentages as given are byweight. This solution was introduced into the inlet of the extractioncolumn I. Naphtha, e. g. fraction ap proximately heptane or octanegrade, and consisting of a mixture primarily oi parafllnic hydrocarbonscontaining 6 to 10 carbon atoms was introduced at the bottom of thecolumn but above the clearing zone a. The proportions were respectively45 parts by volume of soap solution and 180 parts by volume of naphtha,or a ratio of 1 to 4. The temperature of the column was 120 F.

The soap constituents were drawn oil at the lower clearing zone a insolution in the water and methanol and were subjected to appropriatesteps for recovery of the tall oil acids. For example, the solution wassubjected to acidification with sulphuric acid or the like toprecipitate a mixture of rosin acids and fatty acids that could beseparated from the water-methanol layer and dried. About 19.3 parts byweight of tall oil (mainly acids) was recovered. Subsequently, ifdesired, the rosin acids could be separated from the fatty acids byappropriate technique. One convenient system would involve distillation,preferably under relatively high vacuum. The fatty acids could also beselectively esterified with a lower alcohol such as methyl alcohol orethyl alcohol and separated by distillation or other appropriatetechnique.

The solution comprising primarily unsaponifiable matter, includingsterols such as betasitosterol, higher alcohols (alcohols containing 22carbon atoms or more per molecule) and other constituents, was taken oilin the naphtha phase at the top of column I and washed with water toremove any residual soaps contained therein. The washing operation wasperformed in the manner prescribed, namely by passing the naphthasolution containing the unsaponifiabie material to the bottom of columnII and washing it with water in the latter column in countercurrentflow. Column II was maintained at F. and the water feed was 100 parts byvolume.

The naphtha solution of unsaponifiable matter from which residual soapshad been washed was drawn off from the clearing zone at the top ofcolumn II and the unsaponifiable material was recovered preferably byevaporating the solvent. The yield of unsaponifiable matter was 3.78parts by weight. Sterols were further concentrated by crystallizing themfrom an appropriate solvent. such as a solution of ethyl alcohol andacetone. In this manner, 1.26 parts by weight of the crude sterols oftall oil from northern pine were readily recovered to provide a productmelting within a range of to C. The sterols could have been furtherpurified by appropriate technique, which it is not deemed to benecessary further to describe. a

In similar manner, tall oil from southern pine 76 was subjected to thetreatment of this invention 9 in order to separate a concentration ofunsaponiflable matter and to obtain thesoaps of the fatty acids androsin acids relatively free of unsaponiilable matter. It is to beunderstood that the tall oil of northern pine in many instances ishighly rich in unsaponiflable matter and may contain 8 or 9% or perhapseven more of this material. It would also appear that the unsaponifiablematter from northern pine is relatively low in the long chain alcohols,such as C-22 or higher alcohols, which are difllcult to separate fromtall 011 sterols by conventional methods.

The following constitutes an example illustrating the application of theprinciples of the invention to the fractionation of the solid matter ofsouthern pine tall oil.

Example VI The crude skimmings of the tall 011 from southern pine wereprocessed. These skimmings include about 60% of solid matter, the restbeing essentially water. The skimmings were diluted to a composition ofmethanol, 50% water and tall oil solids in which the tall oil acids werepresent as sodium soaps. The solid matter readily went into solution inthe mixture of water and methanol to provide a solution which wasreadily susceptible of countercurrent extraction ,in the column I. Toeffect extraction of the solution, 45 parts by volume of the latter werein-- troduced at inlet 3 of the column and 135 parts by volume ofnaphtha was passed in at inlet 4. The temperature of the system was 130F.

The solution of soaps, rosin acids and fatty acids in water and methanolwas drawn off from the clearing zone at the bottom of the column and thesoaps were recovered. This could be accomplished by acidification of thesoaps with sulphuric acid or the like to precipitate the free rosinacids and fatty acids. The acids were skimmed off and were then waterwashed to remove soluble impurities, such as sodium soaps and freeacids. Residual solvents were evaporated from the tall oil acids. Theproduct as recovered comprised 22.3 parts by weight of crude tall oilmaterial.

Rosin acids and fatty acids in this mixture could be recovered in ahighly concentrated form by distillation.

The naphtha solution of unsaponifiable material from the southern talloil was drawn oil at the top of column I from the upper clearing zoneand was then subjectedto washing with 90 parts by volume of water incolumn II at a temperature of 105 F. Washed unsaponifiable matter innaphtha was drawn off from the top of clearing zone of column II and1.43 parts by weight of unsaponifiable matter was recovered byevaporation of the naphtha. It could be further purified, for example bycrystallization by a solvent medium such as 6 parts ethyl alcohol and 4of acetone at 0 C. At this temperature, a product comprising primarilythe sterols of the tall oil having a melting point of 110 to 120 C. wasrecovered.

The formulation of systems of tall oil solid matter methanol and. watersuitable for countercurrent extraction with naphtha in the manneralready described is illustrated in Figures 4 and 5 of the drawings. Inthese drawings, the various systems are graphed upon triangularcoordinates in which the side 3-0 is the watermethanol axis, A-B is themethanol-tall oil soap solids axis at the side AC is the tall oil soapsolids-water axis. The area between the branches R and S of the curve inFig. 4 and about the 10% soaps limit constitutes the zone in whichliquid solutions of tall oil solids in water and methanol are obtained.These solutions can be extracted countercurrently with naphtha in themanner previously described into a naphtha phase containing theunsaponifiable material and a watermethanol phase containing most of thesoaps of rosin acids and fatty acids. The unsaponiflable material innaphtha can be drawn off from the clearing zone at the top of column Iand the water-methanol phase containing the soaps can be drawn off fromthe lower clearing zone. The recovery of the various constituents can beconductedin accordance with the technique previously described.

It will be understood that other temperatures than those-specified forthe systems covered by the curves in Figures 2, 3, 4 and 5 may beemployed in column I. The temperature range may, forexample, extend fromroom temperature or about 75 F. up to F.-and will include all of theintermediate temperatures.

Any solution falling between branches of the curve R-S in Figure 4, or Tand U of Figure 5 will be operative at the lower temperature specifled.At other temperatures, certain variations of the curves of course willtake place. It is impossible to illustrate all of the possible systemssince the number of different temperatures is practically unlimited.Most of the systems contemplated by the present invention where methylalcohol is employed as the alcoholic medium will be embraced by theformula:

Of course, the operability of any particular system can be welldetermined by means of sample solutions which can be shaken up inbottled or other appropriate container with naphtha and left to standfor a short period of time. Operable solutions of soap and methylalcohol must be liquid at the temperatures of extraction, must be atleast but partially miscible with naphtha, must not form emulsions andmust separate into phases when shaken, within a period of not more than6 minutes. Solutions that do not separate from naphtha within thisperiod of time are unsuitable for counter-current extraction withnaphtha in the manner above described. The better mixtures will separateusually within a period of 3 minutes or less. As already indicated,ethyl alcohol may also be substituted for isopropyl alcohol or methylalcohol as the alcoholic component of the solvent of the soap mixture.Where ethyl alcohol is so employed, the solids content of the mixturewill be within a range of 5 to 35% by weight. constitute 15 to 70% ofthe mixture.

The forms of the invention herein described are to be considered asbeing merely by way of example. It will be apparent to those skilled inthe art that numerous modifications may be made therein withoutdeparture from the spirit of the invention or the scope of the appendedclaims.

This application is a continuation-in-part of our copending applicationSerial No. 704,314, illed October 19, 1946, now abandoned. and entitledFractionation of Tall Oil.

The alcohol will We claim:

1. A process of obtaining the unsaponifiable matter of tall oil inconcentrated form, which process comprises making up a solution of thetall oil soaps containing the unsaponiflable matter of tall oil from themanufacture of paper pulp in a concentration of about to 25 per cent inisopro yl alcohol and water with the flnal solution containing from to50 per cent of isopropyl alcohol and the remainder water, and extractingout the unsaponifiable matter in said solution by countercurrentlyflowing the solution in contact with naphtha in a ratio of 1 to parts byvolume per part of tall oil soap solution at a temperature of 80 to 130F., by continuously introducing the solution into an upper portion of anextraction zone and continuously introducing naphtha into a lowerportion of the same zone,

drawing oil the solution of isopropyl alcohol and water at the lower endof the zone at a point below that of introduction of the naphtha anddrawing off the solution of unsaponifiable matter in naphtha at theother end of the system at a point above that of introduction of thesolution and evaporating the naphtha from the solution of unsaponifiablematter.

2. A process of obtaining the unsaponiflable matter of tall oil inconcentrated form, which process comprises making up a solution of thetall oil from the manufacture of paper pulp, in a concentration of 5 toper cent in isopropyl alcohol and water with the final solutioncontaining from 15 to 50 per cent of isopropyl alcohol and the remainderwater and extracting out the unsaponifiable matter in said solution bycountercurrently flowing the solution in contact with .5 to 10 parts byvolume of naphtha per part of from the solution of originals in solidsfrom the water and alcohol and recovering the solvents from theresulting solution.

4. In a process of obtaining the unsaponii'iable matter of whole tall011 in concentrated form, the steps which comprise making up a solutionof 5 to 35% by weight of whole tall oil solids comprising rosin acidsoaps and fatty acid soaps of tall 011 and the unsaponiflable matter oftall 011 in 15 to 62% by weight of water and 12 to 65% by weight ofmethanol, then extracting the unsaponiflable matter from the solution byflowing the latter continuously into an elongated extraction zoneslightly below the top thereof and introducing naphtha continuously tothe lower portion of the same zone, slightly above the bottom thereof,the zone being maintained within a range of 75 F. to 150 F., allowingthe solution and naphtha to percolate countercurrently through eachother in intimate contact, drawing oil a solution of tall oil acid soapsin water and methanol at the bottom of the zone below the point of inletof naphtha and drawing on a solution of unsaponiflable matter andnaphtha at acid soaps and fatty acid soaps of tall 011 and tall oil soapsolution at a temperature of 80 to 130 F., by introducing the solutioninto an upper portion of an extraction zone and naphtha into a lowerportion of the zone, removing a naphtha solution of unsaponiflablematter at the upper end of the system at a point above that ofintroduction of the solution of the soaps at the other end of the systemat a point below that of introduction of the na htha, washing thenaphtha solution of unsaponiflable matter with water to remove residualunsaponiilable matter and evaporating oif the naphtha.

3. In a process of obtaining the unsaponifiable matter of whole tall oilin concentrated form, the steps which com rise making up a solution ofwhole tall oil solids comprising rosin acid soaps and fatty acid scansof tall oil along with the unsaponiflable matter of tall 011 in solutionin water and a lower alcohol of a class consisting of methanol, ethanoland iso ropanol, the concentration of solidsbeing 5 to 35%, thepercentage of the alcohol for methanol being in a range of 12-65%, forethanol being in a range of 15-70% for isopropyl being in a range of15-50%, then extracting the unsaponifiable matter from the solution byflowing the solution continuously into an elongated extraction zoneslightly below the top thereof and introducing naphtha continuously to alower portion of the same zone slightly above the bottom thereof, thezone being maintained within a range of 75 F. to 150 F., allowing thesolution and naphtha to percolate countercurrently through each other inintimate contact, drawing oi! a solution of tall oil acid soaps in waterand the alcohol at the bottom of the zone below the point of inlet'ofnaphtha and then drawing the solution of unsaponiflable matter in waterat thp top of the zone between the inlet use the unsaponiflable matterof tall oil in a mixture of water and a lower alcohol of the classconsisting of methanol, ethanol and isopropanol, the percentage of thealcohol in the case of ethanol being in a range of '15 to 70% by weight,in the case of isopropanol being in a range of 15 to 50% by weight andin the case of methanol being in a range of 12 to 65% by weight, thenextracting the unsaponiflable matter from the solution by flowing thesolution continuously into an elongated extraction zone at a pointslightly spaced from the first extremity thereof and introducing asolvent of unsaponiflable matter of a class consisting of diethyl ether,methyl ether, methyl ethyl ether, isopropyl ether, ethyl isopropyl mixedether, methyl isopropyl mixed ether, benzene, toluene, xylene, naphthaand ethylene dichloride in a proportion of 1 volume to 20 volumes pervolume of soap solution, the solvent being introduced continuously intoa portion of the extraction zone slightly spaced from the secondextremity thereof, the zone being maintained within a range of F. to R,allowing the solution and solvent to percolate countercurrently througheach other in intimate contact, drawing off a solution of tall oil acidsoaps in water and the alcohol at the second mentioned extremity of thezone, then drawing of! the solution of unsaponiflable matter in thesolvent thereof at the first mentioned extremity of thezone andrecovering the solvents from the resultant solutions.

6. In a process of obtaining the unsaponiflable matter of whole tall oilin concentrated form, the steps which comprise dissolving whole tall oilsolids comprising rosin acid soaps and fatty acid soaps of tall oil andthe unsaponifiable matter of tall oil in a mixture of water and a loweralkyl monohydric alcohol containing from 1 to 3 carbon atoms permolecule to form a solution which comprises 5 to 35% of said solids, 15to 50% said lower alcohol and the rest of the composition being *water,then extracting the unsaponifiable matter from the solution by flowingthe solution continuously into an elongated extraction zone at a pointslightly spaced from the first extremity thereof and introducing asolvent of unsaponifiable matter of a class consisting of diethyl ether,methyl ethyl ether, isopropyl ether, ethyl isopropyl mixed ether, methylisopropyl mixed ether, naphtha, benzene, toluene, xylene and ethylenedichloride in a proportion of 1 volume to 20 volumes per volume of soapsolution, the solvent being introduced continuously into a portion ofthe extraction zone slightly spaced from the second extremity thereof,the zone being maintained at a temperature within a range of 75 F. to150 F., allowing the solution and the solvent to percolatecountercurrently through each other in intimate contact, drawing ofi asolution of tall oil acid soaps in water and the lower alcohol at thesecond extremity of the zone, then drawing on the solution ofunsaponiflable matter in the solvent thereof at the first mentionedextremity of the zone and recovering the solvents from the resultantsolutions.

ROGER M. CHRISTENSON. STEWART W. GLOYER.

REFERENCES CITED The .following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,218,971 Julian et a1. Oct. 22.'1940 2,248,346 Gayer et al. July 8, 1941 2,273,045 Julian et a1 Feb.17, 1942 2,275,075 Gayer et al. Mar. 3, 1942 2,280,815 Fernholz Apr. 28,1942 OTHER REFERENCES Book of Standards, A. S. T. M., 1944, part III.

1. A PROCESS OF OBTAINING THE UNSAPONIFIABLE MATTER OF TALL OIL INCONCENTRATED FORM, WHICH PROCESS COMPRISES MAKING UP A SOLUTION OF THETALL OIL SOAPS CONTAINING THE UNSAPONIFIABLE MATTER OF TALL OIL FROM THEMANUFACTURE OF PAPER PULP IN A CONCENTRATION OF ABOUT 5 TO 25 PER CENTIN ISOPROPYL ALCOHOL AND WATER WITH THE FINAL SOLUTION CONTAINING FROM15 TO 50 PER CENT OF ISOPROPYL ALCOHOL AND THE REMAINDER WATER, ANDEXTRACTING OUT THE UNSAPONIFIABLE MATTER IN SAID SOLUTION BYCOUNTERCURRENTLY FLOWING THE SOLUTION IN CONTACT WITH NAPHTHA IN A RATIOOF 1 TO 20 PARTS BY VOLUME PER PART OF TALL OIL SOAP SOLUTION AT ATEMPERATURE OF 80 TO 130*F., BY CONTINUOUSLY INTRODUCING THE SOLUTIONINTO AN UPPER PORTION OF AN EXTRACTION ZONE AND CONTINUOUSLY INTRODUCINGNAPHTHA INTO A LOWER PORTION OF THE SAME ZONE, DRAWING OFF THE SOLUTIONOF ISOPROPYL ALCOHOL AND WATER AT THE LOWER END OF THE ZONE AT A POINTBELOW THAT OF INTRODUCTION OF THE NAPHTHA AND DRAWING OFF THE SOLUTIONOF UNSAPONIFIABLE MATTER IN NAPHTHA AT THE OTHER END OF THE SYSTEM AT APOINT ABOVE THAT OF INTRODUCTION OF THE SOLUTION AND EVAPORATING THENAPHTHA FROM THE SOLUTION OF UNSAPONIFIABLE MATTER.